Relationship between serum 25-hydroxy vitamin D levels, knee pain, radiological osteoarthritis, and the Western Ontario and McMaster Universities Osteoarthritis Index in patients with primary osteoarthritis

Abstract

Objective This study aims to detect the relationship between serum 25-hydroxy vitamin D (25-OHD) levels in patients with primary osteoarthritis (OA) of the knees and with other disease parameters of OA, mainly radiological findings, functional assessment using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and pain [numerical rating scale (NRS)]. Patients and methods We studied 140 consecutive patients with primary knee OA, 110 female patients and 30 male patients. They were clinically, radiologically, and also functionally evaluated regarding OA; pain was also assessed using NRS, and serum 25-OHD, serum parathormone, serum calcium, phosphorus, and alkaline phosphatase were measured. Results In our patient sample, we found that 90 (64.3%) patients had lower 25-OHD levels. The mean serum 25-OHD was 35.77 ± 14.6 (range 10.62-71.82) ng/ml; 25-OHD was negatively significantly correlated with patients′ age (P = 0.013, r = −0.236), radiological degree of OA (P = 0.036, r = −0.20), WOMAC (P < 0.0001, r = −0.337), and NRS for pain (P < 0.0001, r = −0.580). When comparing between patients with hypovitaminosis, 25-OHD less than 40 ng/ml, and patients with desirable 25-OHD levels, we found that radiographic grading of OA was significantly higher in the hypovitaminosis group (t = 2.024, P = 0.045); WOMAC was also significantly higher in the hypovitaminosis group (t = 3.226, P = 0.002) and NRS was also higher in the hypovitaminosis group (t = 4.468, P < 0.0001). Conclusion 25-OHD deficiency is prevalent in our patients suffering from OA; in addition, 25-OHD may play a role in patients suffering from OA.

Keywords

• 25-hydroxy vitamin D, Kellgren-Lawrence grade, osteoarthritis, parathormone, Western Ontario and McMaster Universities Osteoarthritis Index